Trading on C/L eliminates 99% of your market. First, you need to find someone who wants to trade, and who has a nice MTB. Secondly, that MTB needs to be your size. Who typically has such an item? A flipper (someone who has a garage full of bikes in various styles and sizes) and who will trade an inferior MTB for your road bike.

For instance, lets see you see an ad for the "perfect" hybrid for sale in your area. While you are attempting to make a trade, with someone who just wants to sell their bike, another buyer arrives with cash in hand. Guess who ends up with the bike?

Instead, trade CASH for the MTB you desire, by selling your bike. You will need to brush up on your marketing, take a quality full size picture, with a neutral background, hosted by one of the on line hosting sites, and create a nice ad (no crappy small C/L picture). The difference in creating such a quality ad can be +/- 50% or more. Buyers have no imagination.

The good news around here, with the right marketing, you will end up with extra cash in your pocket. Road/racing bikes command a hefty premium over hybrids.